$ { {-4} \times \left[\begin{array}{rrr}{-1} & {0} & {3} \\ {2} & {-1} & {0}\end{array}\right] = {?} } $
Answer: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-4}\times{-1} & {-4}\times{0} & {-4}\times{3} \\ {-4}\times{2} & {-4}\times{-1} & {-4}\times{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{4} & {0} & {-12} \\ {-8} & {4} & {0}\end{array}\right]}$